Space reclamation system and method for use in connection with tape logging system
First Claim
1. A valid data item update retrieval and storage subsystem for copying valid ones of a plurality of data item updates serially recorded on a source storage medium, onto a target storage medium, each data item update having a data item identifier which is one of a set of data item identifier values, the valid data item update retrieval and recording arrangement comprising:
- A. a storage medium directory including a series of directory entries each identifying, for a corresponding one of the series of data item updates recorded on said source storage medium, the data item identifier associated with said corresponding one of the series of data item updates;
B. a data item identifier flag set comprising a plurality of data item identifier flags, each associated with a data item identifier, each flag having a valid condition indicating that the source storage medium has a valid data item update associated with the respective data item identifier flag'"'"'s associated data item identifier stored thereon, and at least one other condition;
C. a valid data item update identifier for using the storage medium directory and said data item identifier flag set to identify a set of valid data item updates on said source storage medium, the valid data item update identifier scanning the directory entries in said directory in reverse in reverse order and, for each directory entry, determining whether the data item identifier flag associated with the data item identifier contained in the directory entry indicates that the source cartridge has a valid data item update associated with the respective flag'"'"'s associated data item identifier stored thereon and, if so, determining that the data item update associated with the directory entry is a valid data item update;
D. a valid data item update transfer control for providing valid ones of the data item updates as identified by said valid data item update identifier from the source storage medium for storage on the target storage medium.
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0 Petitions
Accused Products
Abstract
A digital data processing system comprises a host information generating device, a mass storage subsystem, and a back-up information storage subsystem. The host information generating device generates information and provides it to the mass storage subsystem for storage. The mass storage subsystem receives the generated information from the host information generating device and transfers the generated information to the storage element for storage, and further transfers the generated information to the back-up information storage subsystem. The back-up information storage subsystem receives and stores the generated information from the mass storage subsystem'"'"'s control element. The back-up information storage subsystem includes a filter/buffer module, a tape log module and a reconstruction module. The filter/buffer module filters and buffers the information received from the mass storage subsystem and provides the buffered information to the tape log module for storage. The tape log module stores the information received from the filter/buffer module in logging fashion on tape cartridges. The filter/buffer module filters the information received from the mass storage subsystem so as to reduce the amount of information to be logged, so that, if the host changes the information while it is being buffered, the filter/buffer module will provide only the most recent information to the tape log module for storage. If a failure occurs in the mass storage subsystem, the reconstruction module can reconstruct the information that was on the failed device using the stored information from the tape log module and the buffered information.
246 Citations
72 Claims
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1. A valid data item update retrieval and storage subsystem for copying valid ones of a plurality of data item updates serially recorded on a source storage medium, onto a target storage medium, each data item update having a data item identifier which is one of a set of data item identifier values, the valid data item update retrieval and recording arrangement comprising:
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A. a storage medium directory including a series of directory entries each identifying, for a corresponding one of the series of data item updates recorded on said source storage medium, the data item identifier associated with said corresponding one of the series of data item updates; B. a data item identifier flag set comprising a plurality of data item identifier flags, each associated with a data item identifier, each flag having a valid condition indicating that the source storage medium has a valid data item update associated with the respective data item identifier flag'"'"'s associated data item identifier stored thereon, and at least one other condition; C. a valid data item update identifier for using the storage medium directory and said data item identifier flag set to identify a set of valid data item updates on said source storage medium, the valid data item update identifier scanning the directory entries in said directory in reverse in reverse order and, for each directory entry, determining whether the data item identifier flag associated with the data item identifier contained in the directory entry indicates that the source cartridge has a valid data item update associated with the respective flag'"'"'s associated data item identifier stored thereon and, if so, determining that the data item update associated with the directory entry is a valid data item update; D. a valid data item update transfer control for providing valid ones of the data item updates as identified by said valid data item update identifier from the source storage medium for storage on the target storage medium. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A method of copying valid ones of a plurality of data item updates serially recorded on a source storage medium, onto a target storage medium, each data item update having a data item identifier which is one of a set of data item identifier values, a set of said valid data item updates for storing on a valid data item update storage medium, the valid data item update retrieval and recording arrangement comprising:
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A. providing a storage medium directory including a series of directory entries each identifying, for a corresponding one of the series of data item updates recorded on said source storage medium, the data item identifier associated with said corresponding one of the series of data item updates; B. providing a data item identifier flag set comprising a plurality of data item identifier flags, each associated with a data item identifier, each flag having a valid condition indicating that the source storage medium has a valid data item update associated with the respective data item identifier flag'"'"'s associated data item identifier stored thereon, and at least one other condition; C. for using the storage medium directory and said data item identifier flag set to identify a set of valid data item updates on said source storage medium, the valid data item update identifier scanning the directory entries in said directory in reverse in reverse order and, for each directory entry, determining whether the data item identifier flag associated with the data item identifier contained in the directory entry indicates that the source cartridge has a valid data item update associated with the respective flag'"'"'s associated data item identifier stored thereon and, if so, determining that the data item update associated with the directory entry is a valid data item update; D. providing valid ones of the data item updates as identified by said valid data item update identifier from the source storage medium for storage on the target storage medium. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36)
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37. A valid data item update retrieval and storage subsystem for copying valid ones of a plurality of data item updates serially recorded on a source storage medium, onto a target storage medium, each data item update having a data item identifier which is one of a set of data item identifier values, a set of said valid data item updates for storing on a valid data item update storage medium, the valid data item update retrieval and recording arrangement comprising:
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A. a digital data processor; and B. a control subsystem for controlling the processor, the control subsystem comprising; i. a storage medium directory including a series of directory entries each identifying, for a corresponding one of the series of data item updates recorded on said source storage medium, the data item identifier associated with said corresponding one of the series of data item updates; ii. a data item identifier flag set module for enabling the processor to maintain a data item identifier flag set comprising a plurality of data item identifier flags, each associated with a data item identifier, each flag having a valid condition indicating that the source storage medium has a valid data item update associated with the respective data item identifier flag'"'"'s associated data item identifier stored thereon, and at least one other condition; iii. a valid data item update identifier use the storage medium directory and said data item identifier flag set to identify a set of valid data item updates on said source storage medium, the valid data item update identifier scanning the directory entries in said directory in reverse in reverse order and, for each directory entry, determining whether the data item identifier flag associated with the data item identifier contained in the directory entry indicates that the source cartridge has a valid data item update associated with the respective flag'"'"'s associated data item identifier stored thereon and, if so, determining that the data item update associated with the directory entry is a valid data item update; iv. a valid data item update transfer control for enabling the processor to provide valid ones of the data item updates as identified by said valid data item update identifier from the source storage medium for storage on the target storage medium. - View Dependent Claims (38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54)
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55. A control subsystem for use in connection with a processor to form a valid data item update retrieval and storage subsystem for copying valid ones of a plurality of data item updates serially recorded on a source storage medium, onto a target storage medium, each data item update having a data item identifier which is one of a set of data item identifier values, a set of said valid data item updates for storing on a valid data item update storage medium, the control subsystem comprising:
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A. a storage medium directory including a series of directory entries each identifying, for a corresponding one of the series of data item updates recorded on said source storage medium, the data item identifier associated with said corresponding one of the series of data item updates; B. a data item identifier flag set module for enabling the processor to maintain a data item identifier flag set comprising a plurality of data item identifier flags, each associated with a data item identifier, each flag having a valid condition indicating that the source storage medium has a valid data item update associated with the respective data item identifier flag'"'"'s associated data item identifier stored thereon, and at least one other condition; C. a valid data item update identifier use the storage medium directory and said data item identifier flag set to identify a set of valid data item updates on said source storage medium, the valid data item update identifier scanning the directory entries in said directory in reverse in reverse order and, for each directory entry, determining whether the data item identifier flag associated with the data item identifier contained in the directory entry indicates that the source cartridge has a valid data item update associated with the respective flag'"'"'s associated data item identifier stored thereon and, if so, determining that the data item update associated with the directory entry is a valid data item update; D. a valid data item update transfer control for enabling the processor to provide valid ones of the data item updates as identified by said valid data item update identifier from the source storage medium for storage on the target storage medium. - View Dependent Claims (56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72)
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Specification